Tails of a Feather
by Supervillegirl
Summary: Third in Tail series. John and Sherlock find another merman.


Title

 _Sherlock clung to consciousness as he tried to tread water. His limbs wouldn't cooperate properly, and his head kept dipping back under the surface. Luckily, his brain was still with it enough to hold his breath when he went under, although that probably didn't mean much; breathing was one of the strongest survival instincts the brain was in charge of. He tried opening his eyes to take a look around, but everything was blurry and out of focus. He kicked his feet and reached his arms out, feeling something hard and irregular at his right fingertips. He pushed himself in that direction and clung to what had to be a rocky outcropping, dropping his head to the rock and giving himself time to breathe and sort things out._

Where am I? _he wondered._ A lake? A river? What am I doing here?

 _The last thing he remembered was chasing his burglary suspect. The man had taken off into the nearby woods and had fallen through a thin patch of earth into a cave system. Sherlock had followed and finally caught up to him next to—_

Oh…of course…

 _The man had gotten in a lucky shot and knocked Sherlock into the cave pool next to them. Sherlock's head had hit something on the way down—probably the edge of the pool—and had left him with a nasty concussion._

 _Sherlock slowly opened his eyes and looked up in front of him, blinking as the room came into focus. Sure enough, he was in the middle of a cavern, and the suspect was gone, probably off to find a way out. He frowned as the room became more clear. It appeared to be brighter in here than it had been in the rest of the caves. It probably had to do with the lights rising into the air around him._

 _His eyes widened as he turned—one arm still on the edge of the pool—to look at the water he was floating in. The water was churning as though it were a giant jacuzzi, and small beads of light were rising from the surface of it._

"Halfway through the night, light suddenly poured down into the room. It was a full moon that night, and it was starting to move overhead, and it shone down through the hole in the cave roof. The water started churning like it was a hot tub or something. And these…little beads of light—almost like sparks—started rising from the water. It went on for a while, but I never thought to get out. I don't know how to explain it, but it felt…right, you know."

"What that moon pool had done to me…was turn me into a merman."

 _Sherlock looked up above him, and there it was: the full moon. It was shining down through a hole in the ceiling of the cavern, and it was already starting to pass out of view._

How long have I been in here? _he wondered._

 _He looked down at the water around him. It was just as John had said: he felt totally at peace, like he belonged there. He found himself almost mesmerized by what was happening, and before he knew it, it was over. The moon had passed out of sight, and the water settled to its calm stillness._

 _Sherlock glanced down at his legs as they lazily moved back and forth to help keep him afloat, wondering if this was the last time he would see them like this._ What just happened to me?

"Are you all right?"

Sherlock Holmes startled slightly and looked up at John across the kitchen table. "Hmm?"

Dr. John Watson used his fork to gesture at him. "You've been holding that piece of toast for the last five minutes."

Sherlock glanced down at the toast he was holding up in front of himself, and he blinked a few times as he lowered it.

"Are you all right?" John asked again. "You've been a bit off the past few days, ever since you came back from America."

 _Oh, nothing to worry about John,_ Sherlock thought. _I just chased my suspect into a cave and fell in a moon pool during a full moon._

"It was an intriguing case," Sherlock replied. "I'm still trying to piece things together."

John watched him for a moment before going back to his breakfast. "You going to tell me about it this time?"

"Mycroft swore me to secrecy," Sherlock lied, although not without a twinge—more like a punch in the gut—of guilt.

John glanced up at him. "That's never stopped you before." He took a bite of his beans, staring at him.

Sherlock had to smirk before he stared down at the table, thinking.

 _Go on! If anyone will understand, it's_ _ **him**_ _!_

 _He's your best friend._

 _He's going to find out sooner or later._

 _He's your_ _ **only**_ _friend._

 _ **He**_ _told_ _ **you**_ _, now_ _ **you**_ _tell_ _ **him**_ _._

Sherlock looked back up at John, who was now staring at him expectantly. He let out a breath and opened his mouth to speak.

 _Knock-knock_

Sherlock looked up at the door that led out into the stairwell landing as John turned in his seat.

Detective Inspector Greg Lestrade stood in the doorway. "Got a case for you if you want it."

"Excellent!" Sherlock exclaimed, jumping up from his seat to grab his coat. He didn't even care what it was, as long as it got him away from this conversation.

* * *

Sherlock moved around the kitchen of the restaurant, studying the body sprawled on its back. He glanced around the room, picking up little clues and observations as he went. Pretty soon, he had it figured out.

He came to a stop near the door and turned to face the room, clasping his hands behind his back. "This man was killed by a single blow to the head, but it was no accident. The machinery that supposedly fell on him shows no damage upon impact. It was placed there. Conclusion: he was murdered."

The swishing-scratching sound of one of those coverall suits fell upon his ears as someone entered the room behind him.

"Has he finished yet?" Anderson muttered behind him. "So the professionals can get to work?"

Lestrade frowned. "What happened to you?"

"It's started raining," Anderson replied.

 _Oh, wonderful,_ Sherlock thought with an eye roll. _Now, I'll_ _ **have**_ _to tell John since I can't leave the building._

"And me without my umbrella," muttered Lestrade.

A cold prickling made itself known on Sherlock's hands, and his eyes widened as he spun around to see Anderson passing close to him with his forensics case, which was dripping rain water. Sherlock pulled his hands in front of him to see rain drops on them. Mentally counting down from ten, Sherlock turned to the rest of the room.

"I'm sure even you should be able to handle it from here," he quickly rattled off. "If you'll excuse me."

Turning and quickly striding out of the kitchen, he already realized his mistake: excusing himself. He was only ever polite—if that—when he was covering something up. And John would know that.

Calculating how much time it would take to get to different rooms of the restaurant, he deduced he would just barely make it to the storage pantry. He hurried—but didn't run; that would cause more suspicion—in that direction and slammed the door behind him. He had one second in which to let out a sigh of relief before the change swept over him and he fell flat on his face.

* * *

John frowned as Sherlock swept hurriedly out of the room, sensing something was wrong. Sherlock was _never_ polite to other people unless something was wrong. John glanced at Lestrade and then headed after his friend. Sherlock's coat was just disappearing into the storage pantry as he slammed the door, closing himself in. His concern jumping up a notch, John hurried to the door, reaching it just as there was a great thud in the pantry. He tried the door, but it was locked somehow. Or it was blocked.

"Sherlock?" John called, his heart starting to pound when there was no answer. "Sherlock!"

"I'm fine!" Sherlock called back irritably. "Go away!"

"Sherlock, I'm not an idiot!" John replied. "What's wrong?"

John heard a faint sigh before Sherlock said, "Are you the only one out there?"

John glanced up at Lestrade, who had joined him. "Greg—" he stopped himself, "Lestrade's here, too."

"He moves to the end of the hall, then I let you in," Sherlock told him sternly.

John glanced at Lestrade, now deeply worried. This was bizarre behavior, even for Sherlock. But if it got him in to see what was wrong with Sherlock…

John nodded to Lestrade, who moved back to the kitchen entryway at the other end of the hall, and then he motioned to him to stay there. "All right, he's gone."

"Hold on," said Sherlock.

There were many great scraping sounds like something being dragged across the floor, light thuds as items were bumped against and Sherlock's quiet grunts of exertion. Finally, the doorknob turned, and the door popped open a mere centimeter. John immediately pushed the door open.

"Careful," came Sherlock's voice from behind the door.

John started to turn to look behind it and was brought up short by a long merman tail on the floor, all varying shades of blue and white—just like his own. John's eyes slowly moved from the fin at the bottom and up the scaled length as he moved so he could look behind the door. There was Sherlock, lying on his back, propped up on his elbows, shirtless and with his tail— _his tail!_ —sticking out from behind the door.

John wasn't aware that his jaw had dropped. Or that the door was still open. Or that Sherlock was staring up at him with open guilt on his face. All he could do was stare down at the tail—the _merman_ tail—on his supposedly best friend.

 _He's a merman?_ John wondered. _Why didn't he tell me? Why pretend that he'd never heard of such a thing three months ago when he found out about me?_

"John—" began Sherlock.

"This whole time?" John asked, his voice tight. "You were just like me? Gotta say, Sherlock, well done. I thought you truly were finding out about mermen for the first time."

"John?" came Lestrade's voice, drawing closer.

John immediately closed the door before he got close enough to see anything.

"I was not a merman when I found out about you," Sherlock told him.

John looked down at him disbelievingly. "Really?" He turned and moved to the shelves opposite the door.

"I would not lie like that," said Sherlock.

"Oh, come on," said John, turning towards him and crossing his arms. "This is totally something you would do."

Sherlock paused and then nodded. "Yes, but not to you, not about this."

John only stared at him, not sure whether to let him off the hook or not.

"Come on, John, think," Sherlock told him. "Could I have faked my shock _that_ well?"

John clenched his jaw, wanting to be mad about the fact that Sherlock hadn't told him about this until he had been forced to, but knowing Sherlock had not really done anything wrong. He sighed and moved over towards him. "When did it happen?"

"This last full moon," Sherlock replied.

John nodded in realization. "In America."

"I chased my suspect into the woods, we ended up in a cave, and he hit me over the head," Sherlock explained. "I fell into a pool, and by the time I was coherent enough to get my bearings, the moon was already overhead."

"Did the suspect see anything?" asked John.

"No, he had run off," said Sherlock.

John nodded. "Why didn't you tell me?"

Sherlock hesitated and then said in a small voice, "That would've made it real."

John smiled in understanding.

"I was going to tell you this morning," Sherlock told him.

"And then Lestrade came in with a case," John finished for him. "Right." He pointed down at the tail. "I'm assuming you can pull yourself together?"

Sherlock's gaze dropped to his tail, and he refused to look back up at John.

"What?" asked John with a frown.

"I haven't figured that out yet," Sherlock muttered, eyes still fixed on his tail.

John stared at him, trying to stop the smile appearing on his face. "Sherlock Holmes can't figure out how to use his powers?"

"Oh, shut up!" snapped Sherlock gloomily.

"I'll teach you later," John laughed as he stretched his hand out over Sherlock's tail.

Steam started rising from the scales as John's hand slowly closed into a fist.

Sherlock gave a frown. "That feels very strange."

"Have you gotten wet before?" asked John as he concentrated.

"Once, the morning after the full moon," said Sherlock. "Tested it in the hotel bath."

"And you had to air-dry?" asked John in surprise. That would have taken forever, and Sherlock was not known for his patience.

Sherlock gave a shrug that was only slightly embarrassed. "Hair dryer."

Before long, steam filled the room, and Sherlock was lying on the floor in his suit, scarf and coat.

John offered him a hand and pulled him to his feet. "So…what are we going to tell them?"

"About what?" asked Sherlock, brushing the back of his coat sleeves off.

"You did make a bit of a scene out there," John reminded him.

Sherlock paused. "I did, didn't I?"

"You had a bad migraine this morning, and now, you're having a bad reaction to the medicine you took for it," suggested John. "Just act disoriented, and I'll say I'm taking you to the hospital."

"It's raining," Sherlock pointed out.

John nodded, having already thought that through. "I'll take care of both of us." He reached over and grasped Sherlock's arm as though to support him. "Just don't break contact with me while we're out there."

"I always seem to underestimate you, John," said Sherlock, giving his hair a slight ruffle to make himself look more disheveled.

"Don't mention it," muttered John, reaching for the doorknob. "Now, act ill." He pulled the door open as he felt Sherlock slump slightly in his grip.

They had attracted more attention while they had been in there. Now, Anderson and Donovan were standing in the corridor with Lestrade.

"Everything all right?" asked Lestrade, his eyes straying over to Sherlock.

"Yeah, he'll be fine," John told them. "Just a bad reaction to some paracetamol he took this morning. He's a bit disoriented."

Sherlock started pulling slightly at John's grip—just enough to sell the story. "John, it's too many people. I can't—"

"Yes, you can," John told him firmly, turning him to look him in the eye. "Just focus on me. Focus on my hand." He gave the hand gripped to Sherlock's arm a pat. "It's only a little ways to the cab, and then, we'll be at the hospital. They'll fix you. All right?"

Sherlock gave a nod and used his other hand to grab onto the arm John was holding onto him with.

"Okay," said John. He turned back to the others to see them looking at Sherlock in surprise. "It must be an allergic reaction or something. I'm taking him to the hospital." He started leading Sherlock down the hall towards the dining area and front door.

"Need my car to get there faster?" called Lestrade.

"No, it's not life-threatening," John called back. "We'll be fine."

The few officers gathered in the dining area of the restaurant looked towards them in shock.

"Excuse us," John told them. He looked up through the glass windows at the street outside, and it was pouring. This would be a little more difficult than usual. He would have to keep the water starting to pool on the pavement away from their feet.

They reached the front door, and John stopped, turning Sherlock to face him. Seeing that the officers were all some ways away from them, John lowered his voice while grabbing hold of Sherlock's shoulders, trying to make it look like he was comforting him.

"It's raining hard enough for this to be more difficult," John muttered in a low voice. "I'm gonna need more contact than just a hand on your arm."

Sherlock just barely managed to keep from rolling his eyes. "How much more humiliation must I endure?"

"I thought you didn't care what people think," said John with a small smile.

"Apparently, it comes and goes," said Sherlock, holding back his own smile. He then began to try to pull away from the door.

"Hey, hey," said John, holding him in place. "It's just a short walk to the cab. Look, there's hardly anyone outside. Then it'll just be you and me in the cab. Come on." He wrapped his left arm around Sherlock's shoulders and led him to the door, muttering, "Just be grateful there are no reporters yet."

John braced himself, imagining a skintight forcefield around the two of them, and then he pushed open the door and pulled—yes, pulled; he could feel Sherlock starting to instinctively push back away from the rain—Sherlock out into the downpour. Fortunately, John felt not a single drop of rain, on him or Sherlock. It had worked, just as he had known it would.

"Come on, you're not scared of the rain, are you?" John asked over the roaring downpour.

"Very funny," Sherlock bit back.

John carefully raised his right arm, trying not to break his concentration. "Taxi!"

A few seconds later, one pulled up, and John opened the door by placing his hand just over the handle as if he was pulling it but then using telekinesis to pop the latch and pull it open (you could only dry so much of the handle when it was raining). Easing his arm slightly away—but still in contact—from Sherlock's back, John let his friend get in first, and he climbed in after him.

"221B Baker Street," Sherlock called to the cabbie, and off they went.

John had released his contact with Sherlock when they had gotten into the cab, but he had held out his hand, controlling the water clinging to his "forcefield." Now, he slowly moved his hand so the water moved through the air down to the floor. The two of them breathed out a sigh of relief, looked over at each other and promptly burst into laughter.

"Did you see their faces?" laughed John.

"I thought Donovan's eyes were going to fall out of her head," chuckled Sherlock.

"'Oh, my God,'" mocked John. "'He's human after all!'"

That got them going again.

"Could you imagine their faces if they knew the truth?" asked John in a quiet voice after the laughter died down.

"No, and I don't want to," muttered Sherlock.

"So…" said John, looking over at his friend, "you think Mycroft knows?"

Sherlock groaned, closing his eyes and dropping his head back against the seat.


End file.
